Antiunitary operator (source code)

= Antiunitary operator
{title2=$\langle Au,Av\rangle=\overline{\langle u,v\rangle}$}
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= Antiunitarity
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An antiunitary operator between complex <Hilbert spaces> is a surjective <antilinear map> satisfying the displayed <inner product> identity. It preserves <norms> but conjugates scalars. In a chosen <orthonormal basis> it is $UK$, with $U$ a <unitary operator> and $K$ coefficientwise <complex conjugation>. Conversely any such $UK$ is antiunitary. Antilinearity by itself does not preserve norms.